Manufacture of titanous chlorid.



PATENTED MAR. 17, 1903.

H. SPENGE. MANUSRACTURB-'OP TITANo-UsroHLomn.

` '-'AIIVPPLIGATION FILED AUG. 15, 1902. N0 MODEL.

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UNITED STATES 4PATENT OEEIcE.

HOWARD SPENOEJOF MANCHESTER, ENGLAND.

MANUFACTURE OF TITANOUS CHLORID.

SPECIFICATION forming part of Letters Patent No. 723,217, dated March 17, 1903.

l Application liledAugust 15, 1902. Serial No. 119,803. (No specimens.)

To @ZZ whom t may concern,.-

Be it known that I, HOWARD SrENcua subject of the King of Great Britain and Ireland, and a resident of Manchester, in the county of Lancaster, England, have invented new and useful Improvements in the Manufacture of Titanous Chlorid, of which the following is a specification.

` The powerful reducing properties of titanous chlorid (titanium sesquichlorid) have been known for many years; but this knowledge has until quite recently been of scientic importance only, owing to the factthat there existed no known method of preparing it asa commercial product.

The only crystallized compound of `ous chlorid Glatzel in the Deut. Chem. Ges. Ber., 9s., 1832, as consisting ot' TigCl-l-SHzO, in the following terms: I produced the above com? bination by evaporating the violet solution obtained by treating titanium with hydrochloric acid until crystallization took place. The solution gradually became darker and finally became cherryred, depositing very iinely-divided titanic acid, which necessitated repeated tiltrations. Finally I obtained a salt having a green color which did not again action.

dissolve in water to a clear solution, but always separated out small quantities of titanic acid in extremely line division, so that the solution appeared to be opalizing. The solution was violet, but'became discolored after some time and then showed a titanic-acid re- The salt therefore had been subjected to a higher oxidation. Owing to the fact that metallic titanium is unobtainable commercially, lthis method of producing a` titanous chlorid is of nopractical value. It has, however, recently been experimentally ascertained, as is incidentally mentioned in the application `for Letters Patent of the United States, Serial No. 702,566, dated the 18th of March, 1902, that a solution of titanous chlorid could be obtained by electrochemical means. `It was, however, assumed, as stated by Glatzel, that a solution of titanous chlorid could not be evaporated without decomposition, and that therefore a solution prepared by ordinary electrolytical processes was of the highest strength practically obtainable; but I have now ascertained .that

titan-1 yet known was described by E.

i if a solution of titanous chlorid be evaporated under the conditions hereinafter stated, the solution having been prepared substantially as directed, I am thereby enabled to produce a new crystallized compound of titanous chlorid having chemical and physical characteristics different from those possessed by the compound described by Glatzel. The new compound possesses qualities of the highest importance for commercial use as a reducing agent in various manufactures, its reducing power being very much greater than that of theexisting com mercial reducing agents, such as stannous chlorid.j

In carrying out my invention I subject a solution of titanic chlorid, conveniently prepared by dissolving orthotitanic hydrate in hydrochloric acid or by other well-known means, to electrolysis. Such a solution may suitably contain about twenty-tive per cent. of TiCl4.

The accompanying drawing illustrates in vertical section a cell adapted to carry out my invention. two compartments by'a porous diaphragm a and containing a suitable cathode b of lead, for example, in one compartment c and a suitable anode d of carbon, for example, in the other compartment e, I introduce the so# lution of titanic clilorid into the cathodecompartment, and a dilute-acid solution, dilute hydrochloric acid, for example, into the anode-compartment and connect the cathode and anode, respectively, to a suitable source of electric current. I find that I obtain satisfactory results witha current density ofabout two hundred amperes per square meter under a tension of from three to four volts. On closing the electric circuit the TiCl, solution is readily and rapidlyreduced to Ti2Cl6, (or TiOl3,) the liquor being kept at the ordinary or at a .slightly-elevated temperature. The chlorin gas given off at the positiveI pole may be collected and utilized by well-known means. More than ninety per cent. of the TiCl4 is readily converted into TiClB. The solution ofTiOl3 thus produced, containing free hydrochloric acid, is then transferred to a suitable vessel, in which it is concentrated to yield the new crystallized compound. Although the solution thus prepared may be concentrated by ordinary evaporation under atmospheric pres- In such a cell divided int0` IOC sure, I prefer to concentrate it at a lower temperature under reduced pressure. Any hydrochloric-acid vapor given off during the evaporation may be condensed by Well-known means. Unlike Glatzels solution of metallic titanium in hydrochloric acid, which, he states, decomposes during evaporation and requires separation of the precipitated TiO2, I find that my solution remains quite stable during evaporation. Any slight decomposilion which may occur at the commencement of the concentration of the liquor produced in the way I have described is due not to any decomposition of the titanous chlorid, but to the decomposition of any small remaining quantity of TiOl4 which has escaped reduction during electrolysis. The concentration of the liquor continued until a specific gravity of about 1.5 at 65 to 70o centigrade is obtained yields on cooling an abundant crop of crystals of the new titanons compound, which may then be separated from the mother-liquor. I may also continue the concentration to a higher degree and on cooling the liquor obtain the product as a solid cake, which is a convenient commercial form, or I may continue the evaporation only so far that on cooling the product is in the form of a concentrated aqueous solution. v

The new compound produced as hereinbefore described differs essentially from that described by Glatzel, inasmuch as its color is of a fine lilac shade, showing more violet.

when damp, Whereas Glatzels product is green. The new compound forms a very stable body, soluble with extreme readiness in Water with a clear solution. It is highly suitable for manufacturing on the large scale and for the preparation by double decomposition or by other means of other titanous componnds.- 4

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The hereinbefore-described process of obtaining titanous chlorid from titanic chlorid, which consists in subjecting an aqueous solution of titanic chlorid to the action of an electric current between a cathode and an anode in an electrolytic cell divided by a porous partition into a cathode-compartment and an anode-compartment, the titanic-chlorid solution being contained in the cathodecompartment while the anode-compartment contains a dilute-acid solution.

2. The'new compound of titanous chlorid obtained by electrolyzing a solution containing titanic chlorid, which compound is a powerful reducing agent easily soluble in Water, and is of a lilac color.

In testimony whereof I have signed my Aname to this specification in the presence of two Subscribing witnesses.

HOWARD SPENOE. Witnesses:

ARTHUR MILLWARD, J As. STEWART PRoUDFooT. 

